Flat x-bar switch



April 3, 1956 J. KRUITHQF ET AL 2,740,844

FLAT X-BAR SWITCH Filed April 3, 1952 4 Sheets-Sheet l A 7' TOR/VE? 4 Sheets-Sheet 2 J. KRUITHOF ETAL FLAT x-BAR SWITCH April 3, 1956 Filed April 5. 1952 April 3, 1956 J. KRUITHOF ET Al. 2,740,844

FLAT x-BAR SWITCH Filed April 3, 1952 4 Sheets-Sheet 3 F/GS y MM).

A TTOR/VEV April 3, 1956 Filed April 3. 1952 J. KRUITHOF ET AL FLAT X-BAR SWITCH 4 Sheets-Sheet 4 United States Patent O FLAT X-BAR SWITCH Jakob Kruithof, Louis Jacques Ghislain Nys, and -ules Louis Joseph Donceel, Antwerp, Belgium, assignors t International Standard Electric Corporation, New York, N. Y., a corporation of Delaware Application April 3, 1952, Serial No. 280,253 Claims priority, application Netherlands April 13, 1951 7 Claims. (Cl. 179-2154) The invention relates to a tiat electric switch to be used for example in telecommunication systems and affords the possibility of connecting one inlet with a selected one out of a plurality of outlets. Further, a combination of such switches can be used, whereby some essential parts function in common for several switches. In this manner a multi-switch is obtained which may then perform a connection between any out of a plurality of inlets and a selected outlet.

Such switches are already known and have for example been disclosed in U. S. Patent No. 2,651,682, and in our co-pending application filed April 3, 1952, bearing Serial No. 280,252, entitled Electric Switch.

The present invention relates to a particular manner in which an individual switch is constructed. individual switc here indicates a switch giving access from one inlet to any out of a plurality of outlets.

The main object of the invention is to obtain an individual switch which has the smallest possible dimensions while at the same time is economical to manufacture and fully reliable in its operation.

Another object of the invention is to realize a switch whose smallest dimension, i. e. thickness, is as reduced as possible whereby a large number of such switches may be piled up on top of one another to obtain a multiswitch of reasonable dimensions.

A feature of the invention relates to an electric switch with a plurality of outlets and comprising a first set of fixed parallel conductors, i. e. outlet conductors, a second set of parallel conductors substantially perpendicular to those of the first set and a set of contact fingers movable substantially perpendicular to both sets of conductors and designed to eliect contact between a group of conductors of the second set and a group of conductors of the lirst set corresponding to a particular finger, said conductors of the second set carrying resilient contact extensions which may be displaced, by said contact fingers, into contact with corresponding conductors of the first set, the displacement occurring in a plane perpendicular to the direction of the conductors of the first set.

The tirst set of iixed parallel conductors might extend in a vertical direction, while the conductors of the second set and the resilient contact extensions thereof extend in a horizontal plane, the contact fingers being also located in a horizontal plane and substantially at right angles to the conductors of the second set. In this way, by having the contact extensions movable in a horizontal plane, no additional height will be necessary to permit the displacement of the contact extensions, whereby the Aheight of the switch will be kept to a minimum, being limited to the height of the ngers compatible with a satisfactory cooperation between the finger and the contact extensions associated therewith.

Another feature of the invention resides in the fact that said resilient contact extensions extend at an angle, e. g. from the direction of the fixed part of the conductors of the second set and are inserted in narrow slots provided in the contact fingers, to permit the latter to ice drive their free ends into contact with corresponding conductors of the first set.

These above mentioned and other objects and features of the invention will become more apparent and the invention itself will be best understood by referring to the following description of an embodiment taken in conjunction with the accompanying drawings which represent:

Fig. 1, a plan View of the front part of the switch;

Fig. 2, a plan view of the rear part of the switch;

Fig. 3, an elevation view of the rear part of the switch;

Fig. 4, an elevation View of the front part of the switch;

Fig. 5 shows a sectional side View of the switch taken along x-x'; l

Fig. 6 shows a plan view of a mechanism used for driving the contact fingers;

Fig. 7 shows a front view of the mechanism shown in Fig. 6;

Fig. 8 shows the manner in which Figs. 1 and 2 should be assembled.

Referring to Figs. 1 and 2, the latter shows the essential part of the switch which comprises a main bracket 1 of suitably rigid material on which is mounted an insulated plate 2 which forms an adequate base-plate for both types of conductors. Holes such as 3 and 3 are pierced in the insulated plate 2 to permit the insertion, perpendicularly to the base-plate 2, of fixed conductors 4 and 4 belonging to a first set of conductors, while by means of suitable screws, another set of conductors may be fixed on the insulated plate 2. These conductors are constituted by fiat metal strips such as 5 which are fixed on the insulated plate 2 by means of screws such as 6 and which comprise contact extensions such as 7 which have been obtained by bending an edge of conductor 5 in a vertical plane at 8. It will be observed that this contact extension 7 carries at its free end a coating of precious metal 9 which, when moved, will come into contact with the fixed conductors such as 4 or 4. Extending traversely across the contact extensions 7 are a plurality of spaced actuating fingers 10, 10'. The contact extension 7 will be driven into contact with the fixed conductor by the finger 10, which finger is provided with a vertical part 11. The part 11 is provided with slots such as 12 (Fig. 5) in which the` extension 7 is engaged. On the other hand, it will be observed from Fig. 5 that the vertical part 11 is also provided with wider slots 12' which will prevent the mechanical association of a contact extension with a finger controlling contact extensions along another line. For example, finger 10 when it is displaced, will not come into contact with extension 7 since the latter fits within the slot 12' which slot is suiiiciently wide to clear extension 7 in either its neutral or displaced position.

As shown best in Fig. 3, the iingers, i. e. 10 and lil are guided in slots 13a and 14a in the vertical parts 13 at the front end, respectively and 14 at the rear end to avoid lateral displacements. hey are also maintained in a vertical direction by means of the clips 15 (front end) and 16 (rear end), which clips are fixed to the main bracket as shown in Fig. 3, by means of the screws 17 and 17 and enclose the fingers within slots 13a and 14a, respectively. The fingers 1G and 10 are provided with shoulder portions 1S (front end) and 19 (rear end), designed to permit ydisplacements of the fingers longitudinally in either sense and to limit in the direction of arrow )"2 (Fig. l) the horizontal displacement under the control of the driving mechanism.

As shown in Figs. 1 and 5, the latter incorporates a clutch mechanism which can first be associated with a driving device which acts in common for a whole row of fingers such as 10 and which is constituted by the horizontal bar 20. On the other hand, the clutch mechanism-is tal'soassociatedw'ithlthe end of the finger to which it relates.

The clutch mechanism is =held in a U-shaped part 2li which is xed to the vertical partvll of the main bracket lA and which is providedlwlth two holesA 22 Iand 22 `at its free ends in which a pivot 23 is held. A tirst clutch lever 24 is rotatably mounted on the pivot 23 and is provided-with a hole 25 which, as shown in Fig. 5, is somewhat larger than thel diameter of the pivot 23 whereby vertical displacements of the free end of the lever 24 are permissible. This rst clutch lever 24- is mounted immediately below the upper part 26 of the second clutch lever 27 which .is also rotatably mounted on the `pivot 23 by means ot holes 2S and 29 respectively provided lin its upper part 26 and Vin its lower part 3h. This second clutch lever $27 cannot, however, suier vertical displacementssince the holes '28 and 29 closely correspond with the diameter of the pivot 23.

As' shown in Fig. 5, the first clutch lever 24 is slightly bent at its end 2da which end acts as a point of fulcrum against the inside portieri 26a ot' the upper part 26 of the second clutch lever 26 by means of the spring 3l which spring is held in place bypivot 23is between the rst clutch lever 242% and the lower part Sil of the second clutch lever 26. As shown in Fig. 5, the outer end of part 26 is bent downwardly at right angles and is in the form of a fork 32 which lits around the free end of the first clutch lever 24.

When it is desired to -elect a contact between the horizontal metal strip (and also the remaining horizontal strips in the same plane), and the vertical conductors t or 4 (and also the other vertical conductors associated with the other horizontal metal strips), the operation of the mechanism is as follows:

First, nger lil which is that which will establish the connection, will be preselected by means of a mechanism (not shown) which will cause the free end of the iirst clutch lever 24 to be displaced downwardly so that it will be inserted in a corresponding slot 33 provided in the horizontal bar 2i?. If a pile-up of switches such as that shown in Figs. l and 2 is used to form a multiswitch, such preselecting mechanism may be constituted by soecalled vertical or select bars which are well known in the crossbar switch technique and which serve a vertical row of ingers such as lit.

`When the iirst clutch lever 24 has been displaced downwardly under the action of the preselecting mechanism, the horizontal bar can then be displaced longitudinally in either sense whereby it will cause the iirst clutch lever 24 to rotate around the pivot 23. For the sake of convenience it will be assumed that a connection is desired with conductors such as 4 whereby the horizontal bar will have to be displaced in the sense of the arrow f1 (Fig. l).

During the downward displacement of the rst clutch lever 24, the second 'clutch lever 27 .is not'aiecte'd since the rst clutch lever 24 is free .to slide .inside the fork 32. When the iirst clutch lever 24 is driven by the horizontal bar 20, the second clutch lever 27 will rotate in a counter-clockwise manner around the pivot 23 by reason of the force exerted by lever 24 against the side of forked end 32. The second clutch lever 27 is formed as a bell crank having a'portion 34, which is at right angles to its arm 26, 4and which will also rotate in a counter-clockwise manner; its end 35 being inserted in a slot 36 provided at the front end of the finger 10 and will drive said nger inthe sense of the arrow fz whereby the contact extensions such as '7, which are inserted in the slots such as 12, will be driven so that their ends 9 will contact the vertical wiressuch as 4.

It is evident that if .a connection with the vertical wires such as 4 is desired, a .displacement of the nger in the direction of the arrow fz is necessary and the horizontal bar .2.0 `Should then be displaced .in the sense of the arrowfi.

It will be observed that in order to obtain a well de- Y hned rest position for -Vmechanism-thas --been provided (Fi-gs.

the iingers such as 10, a centering l nand 5) which comprises a U-shaped profiled bar 37 mounted on the insulated plate 2 by means of the screws 3d, 33. The vertical projections such as 39 and 39' on this part 37 are provided with apertures such as it@ and 40 which are used as pivoting points :for the small centering levers 4l and ltill. These centering levers fill and 4l' are normally held against Vadjacent projections l2 and d2 by means ot the spring 13. The free ends of the centering levers di and di cooperate with the vertical part 11 of the linger .ti by abutting against the front and rear sides, respectively of part 4d in the manner shown in Fig. 5 whererorn it will be appreciated that when the linger is displaced either in the sense of the arrow f2 or in the sense of the arrow fsz, the centering lever il or the centering lever it will rotate around its pivot being driven by the part i4 whereby energy will be stored in the spring 43 which will become tensioned.

In this manner, when the forcewhich maintains the finger in an actuated position .is released, this energy will be used to return the vfinger to Vits original rest position which is therefore well dened. lt will be observed that when the horizontal bar 2@ has been displaced after the rst clutch lever 24, had been depressed, the means which caused said iirst clutch lever 24 to be depressed can now be released since the horizontal bar 20 Will remain associated with the first clutch lever 24 via the slot 33 dueto the rictional pressure exerted thereagainst by the side of the slot. This frictional pressure should be sufficient to overcome the tension of spring 43 and also the back pressure exerted on the contact extensions such as '7 which is transmitted to the finger lil via the side of the narrow slot l2.

Considering Fig. 5, it will be noted that the U-shaped part 2l is used to house two clutch lever mechanisms on top of one another, the bottom one being used in conjunction with the horizontal bar Ztl for the operation of another set of contact lingers which are located below the insulated plate 2. These contact ngers are identical to those located on top of the insulated plate 2 and mounted thereon in a similar fashion. Also, as indicated in dotted lines on Figs. l and 2, horizontal strips such as 5 (dotted lines) will be mounted below the insulated plate 2 by means of screws such as 6'. The upper and lower screws such as 6 and 6' are shown to be staggered since it is assumed that they are made of conducting material such as metal, so as to avoid a short-circuit between top and bottom horizontal strips, which is obviously undesirable since those strips belong 'to different inlets. However, if these screws were made of insulated material, such staggering would no longer vbe necessary and a single screw could readily hold both the top and bottom horizontal strips against opposite sides 'of insulating plate 2.

Referring to Figs. l and 2, the last contact extension on the right-hand side of each horizontal metal strip is shown to lead to an inlet terminal such as 45 for the strip `5 and this permits an additional selection as explained in detail in our said copending application Serial No. 280,252. As shown, these last contact extensions are controlled in the same manner'by means of a contact iinger identical to those already described.

The mechanism for causing the displacement of the horizontal bar such as 20 will now be described with reference to Figs. 6 and 7. It should be assumed that the horizontal bar 20 (Fig. 1) terminates into the end part 46 (Fig. 6) which is provided with a screwedpiv ot 47 on which two auxiliary levers 48 and 49 are mounted on top of one another, as shown in Fig. 7. Except for their endparts 50 and 51, these levers are substantially identical and can be brought into a clutch position when the electro-magnet 52 corresponding with the `horizon tal bar 20 is energized. At this moment, the amature 53 will be attracted towards the core of the electro-magnet 52 whereby the forked extension 54 is rotated in a counter-clockwise manner thereby driving the arm 55 of an intermediate lever 56 which is mounted by means of a screw 58 on an auxiliary bracket 59 fixed to the main bracket 1 by means of the screws 60 and 60 in a clockwise manner around its pivot 57.

The other arm 61 of the intermediate lever 56 will rotate in the same manner exerting a pull on the restoring spring 62, the other end of which is iixed at 63 to the main bracket 1. Asmall extension 64 is mounted on the arm 6l via the screws 65 and 65 and when the electro-magnet 52 is energized, extension 64 will press against the projections 66 and 67 which are integral parts of the auxiliary levers 48 and 49, respectively. Both levers 48 and 49 will, therefore, rotate in a counterclockwise manner around their pivot 47, their free ends 50 and 51 sliding along the guide pins 68, 69 and 79 which are used to guide these free ends and which are mounted on a small bracket 71 screwed to the main bracket 1 by means of the screws 72 and 72.

It will be observed that the slot 73 which is formed between the ends 50 and 51 of the auxiliary levers 48 and 49 will then be brought in line with the horizontal bar 2i) and in this position will surround the edge of a profiled bar 74 which extends in the vertical direction and which can be pivoted either in the sense of the arrow f3 or in the sense of the arrow fg. Once this profiled bar 74 is engaged in the slot 73, it can then be rotated in the sense of the arrow f3 or in the sense of the arrow fs whereby it will drive either the auxiliary lever 48 in the sense of the arrow f1 or the auxiliary lever 49 in the sense of the arrow f'i. In the iirst case, the horizontal bar 20 will be longitudinally displaced in the sense of the arrow f1 and in the other case, in the sense of the arrow i.

During either displacement, the projections 66 and 67 will slide along the extension 64 until, in the second case, the face of the projection 67 will slide oi extension 64 and the auxiliary lever 49 falls back in a clockwise manner under the action of the spring 7S which had become tensioned when the auxiliary levers were lirst rotated. In the rst case, the lever 48 will be the one to fall back but this time under the action of the spring 76 which had become tensioned in the same manner as the spring 75. At this moment, the vertical bar 74 which in the second case maintained the auxiliary lever 48 in its actuated position by frictional pressure against the end 50, can be returned to its original position as shown in Fig. 6. In this case, the lever 4S will then be able to fall back alongside the lever 49. If the vertical bar 74 had been rotated counter-clockwise (in the sense of arrow fs), the lever 49 will then fall back when the vertical bar 74 has returned to its original position.

It will be noted that in either actuated position, the horizontal bar 20 is held by the end 64. Due to the slight staggering of the projections 66 and 67, when it is desired to return the horizontal bar to its original position, this will occur under the back pressure exerted either by the cantilever spring 77 or by the cantilever spring 78 adjacent the bent part 79 integral with the end part 46 of the horizontal bar 20; the stop member 80 fixed to the main bracket 1 defining the rest position of said cantilever springs; the spring 77 exerting a force in the direction of fi and spring 78 exerting a force in the direction of f1. This will occur as soon as the electromagnet 52 is de-energized whereby under the action of the restoring spring 62, the end 64 will return to its original position shown on Fig. 6 thereby releasing the auxiliary levers 48 and 49. The staggering of the projections 66 and 67 is therefore advantageous since the restoring spring 62 will have to overcome the frictional pressure exerted between the sides of the projections and the extension 64. Since in either case the extension 64 is only in Contact with one of the projections 66 or 67, this means a reduction of the release pull which has to be provided by the spring 62 and accordingly of the armature pull which must be exerted by the armature 53 of the electro-magnet 52 to overcome the tension of spring 62.

The part 81 on the opposite side of the forked extension 54 is used to control electrical contacts (not shown) depending upon the electrical condition of the electromagnet 52, while the part 82 which is integral with the cantilever spring 78, is used to control electrical contacts (not shown) when the horizontal bar is displaced.

The mechanism described above is somewhat similar to those disclosed in U. S. Patent No. 2,623,404 and in Belgian Patent No. 495,155 but has the advantage of using simpler parts.

The vertical bar 74 is essentially a part of a servomechanism which is used in common for a plurality of horizontal bars 20, in an analogous manner as the cornmon means used to depress a whole vertical row of lirst clutch levers such as 24. For the horizontal bar 20 which is located immediately below the horizontal bar 20, it is of advantage to use a mechanism similar to that shown in Fig. 6 but located at the opposite end of the bar 20, whereby this can be repeated for each set of two individual switches in a vertical pile-up, thereby enabling the height of the switch to be independent of the size of the mechanism shown in Fig. 6.

As stated above, and as shown more particularly on Fig. 5 which has been drawn at anappreciably enlarged scale, the height of a pair of individual switches is relatively small; a distinct advantage. It is to be avoided that this advantage should not be lost due to the size of the operating mechanism for the horizontal bars. As shown in Fig. 7, the parts used do not have an appreciable height and by using the smallest dimension of the electromagnet 52 in a vertical direction and also due to the alternance of the operating mechanisms at both ends of the horizontal bars, we may avoid losing the benetlt of an individual switch having a very small height.

For example, 24 double individual switches could be piled up on top of one another together with the operating mechanisms for the horizontal bars which are mounted on the main brackets 1; the total height of the multiswitch thus obtained being limited to 48 centimetres.

While the principles of the invention have been described above in connection with specific apparatus, it is to be clearly understood that this description is made only by way of example and not as a limitation on the scope of the invention.

We claim:

l. An electric multi-switch for use in switching systems comprising a rst set of xed spaced parallel conductors, a second set of spaced parallel conductors substantially perpendicular to those of said rst set, each of said second conductors having a rst portion in a lirst plane, a plurality of separated second portions disposed in a row, each in second parallel planes perpendicular to said lirst plane and to said first conductors, the planes of said second portions being disposed at an acute angle to the axis of said row, each of said second portions disposed in overlapping relation to the adjacent second portion of said second conductor and in switching relation between diiIerent of said first conductors, a plurality of spaced, parallel control linger means disposed in a third plane, said third plane perpendicular to said first and second planes and to said first conductors, said linger means including means for engaging corresponding second portions of said second conductors, means for actuating said linger means in a direction parallel to said third plane whereby the second portions of said second conductors are selectively actuated to contact predetermined of said rst conductors.

2. An electric multi-switch as claimed in claim l, wherein each of the second portions of said second conductors comprises a xed part and a resilient part having armoede atfree end, vsaid fmgerrmeans engaging saidrportions at a point between said. parts.

yelectric multi-.switchas claimed in claim l, further comprising a base member of insulating material, a number of said second conductors fastened to one side of said member, the balance of said second conductors fastened to the other side of said member, said member having a plurality ofspaced apertures therethrough, each of said first conductors adapted to pass through ra'different one of said apertures.

4. An electric multisvvitch as claimed in Claim 1, wherein veach of said fnger means comprise a member having a plurality of spaced kslots in one side thereof, alternate slots being or" a size sufficiently smalleno'ugh to engage corresponding second portions of said second conductors, and `intervening of said slots being of a size sufciently large enough to permit movement of said .member Without engaging corresponding adjacent second portions of said second conductors.

'5. An electric multi-switch as claimed in claim 1, wherein said means for actuating said finger .means com prises an actuating bar lying in aplane parallel to said iirstvplane and adiacent an end of said finger means and adapted to move in a direction parallel to its longitudinal axis, said bar having a plurality of slots therein, a plurality of rst clutch levers each adapted to clutch said finger means with said actuating bar, said levers having rest positions and operated positions, means lfor .selectively urging said levers to their operated position, said levers in their operated positions adapted to be selectively urged within the slots of said bar, a plurality of translating levers, both said clutch levers and said translating levers corresponding in number toeach of said iinger means, said translating levers coupled between said clutch levers and said fingers and adapted to translate the direction of motion of said actuating bar to a Vdirection parallel to the longitudinal axes of said 'inger means.

6. An electric multi-switch as claimed in claim 5, further comprising means for maintaining said clutch -ievers in clutched position with said barafter Vselective urging thereof and after withdrawal of said urging, said means comprising the Walls of the slots in said bars and spring restoring means coupled to said fingers for restoring said lingers to normal position after release of said clutch levers by said maintaining means.

7. An electric multi-switch as claimed in claim 5, wherein said means for actuating said'iinger means further comprises a pivoting actuating element, 'an electromagnet having a cooperating armature, a `pair of interponent members 'pivotally `mounted to one end of said actuating bar, resilient means adapted to normally urge said interponent members out of the path of said actuat ing element, a pivotally mounted extension element disposed between said armature and said interponent members, said extension element adapted to urge an end of said interponent members in the path of said actuating element under control of said electromagnet, said extension element having a portion adapted to latch an actuated interponent member in operated position' under control of said electromagnet, resilient Vmeanscoupled to said actuating bar for returning said bar to normal position after said extension element has unlatched said actuated interponent member.

References Cited in the file of this patent UNITED STATES PATENTS 1,339,001 Reynolds a May 4, 1920 1,564,231 Go Dec. 8, 1925 2,479,678 Graybill Aug. 23, 1949 2,550,241 Graybill Apr. 24, i 2,573,453 Knos Oct. 30, 1951 

